The Okayama Association for Laboratory Science, established on December 7, 1982, celebrates its 35th anniversary on December 7, 2017. The association was established to provide opportunities for researchers interested in laboratory animals and animal experiments to assemble beyond the borders of universities, faculties, and institutions to exchange their knowledge and information, as well as help promote their research activities and advancement of community science. The executives, auditors, and other members of the association have organized and held workshops and issued newsletters under the leadership of former presidents. The association has been able to implement research activities for a long period of time thanks to the advice of regular members and the support of supporting members. The workshops have been held twice a year since 1990. A total of 74 workshops(regular conferences), as well as symposiums, have been held and 33 research bulletins (proceedings) have been issued over the last 35 years. We have summarized the workshops and symposiums etc. that have been held.

There are eleven Regional Associations for Laboratory Animal Science in Japan, and each of them conducts independent activities. The present paper introduces the activities of the Regional Associations in 2017 to promote information exchange and interaction among them, starting from those of the northernmost association. In the paper, honorifics for the staff of the office, lecturers, and people who provided us with information on topics have been omitted. For the details, please contact the office of each Regional Association.

To improve the quality of education and research with laboratory animals, Experimental Animal Center (EAC) was established as an animal facility in the Joint Faculty of Veterinary Medicine, Kagoshima University, on September 1st, 2015. We can house and use large-sized (bovine and horse), medium-sized (dog, cat, pig and bird), and small-sized (rodent and rabbit) animals in this facility. Our care and use program of laboratory animals in EAC was fully accredited by AAALAC International on June 9th, 2016. We are using this facility to demonstrate to our students that performance of veterinary care and animal welfare is important for appropriate education and scientific research with laboratory animals in Veterinary Medicine.

The deodorizing effect of weak acid hypochlorous solution against ammonia was investigated. When atomized particles of weak acid hypochlorous solution contacted ammonia, the ammonia concentration decreased in a concentration-dependent manner. The deodorizing effect was also observed against ammonia generated from the used floor cover for mice. When the floor mat was present, the ammonia concentration gently decreased but then rapidly decreased when the floor mat was removed. In the future, we will examine effective spraying conditions for weak acid hypochlorous solution in laboratory animal facilities, and we will also proceed with the validation of effects other than spraying.

It is important to know the optimal timing of mating to produce laboratory animals efficiently and to ensure the preservation laboratory strains. To clarify the characteristics of the male sexual maturity of two laboratory Mictorus strains, namely the “Mar” and “MrosA” strains, which are derived from M. arvalis and M. levis, respectively, the testes and epididymes from 4-, 6-, 8- and 10 week-old males were weighed and compared. Although the tissue weights increased gradually with age in the Mar strain, in the MrosA strain, the weight of the testis increased markedly from 4 to weeks of age and that of the epididymis increased from 6 to 8 weeks of age. In addition, the spermatozoa concentrations in the cauda epididymis at 6, 8, and 10 weeks of age in were measured in each strain. The sperm concentration increased in the Mar strain at 8 weeks versus 6 weeks in the MrosA strain. From these results, it is clear that there are differences in the patterns of the increases in testis and epididymis weight and sperm concentration between the two strains. It was suggested that males of the MrosA strain attain sexual maturity earlier than those of the Mar strain.

Acoel flatworms can move in a variety of ways such as muscular and ciliary movements via cytoskeletal elements and their neural regulations. However, those locomotive mechanisms have not yet been fully elucidated. In this study, we examined the distribution of cytoskeletal elements including filamentous actin (F-actin) and tubulin, and the neuroanatomical organization in an acoelomorph worm, Praesagittifera naikaiensis (P. naikaiensis). Video microscopy revealed the elongation/contraction and the bending/rotation processes, and the ciliary gliding movement of P. naikaiensis. Histochemical and morphological analysis demonstrated that F-actin networks of inner longitudinal and outer circular muscle fibers were positioned along the entire surface of the body, and that the average distance between the circular muscle fibers in the contracted organism was decreased in the anterior region compared with that in the elongated organism. Electron microscopy showed dense bodies on the muscle cells of P. naikaiensis, which indicates that those muscle cells have the appearance of vertebrate smooth muscle cells. Immunohistochemical analysis revealed that -tubulin-positive signals on the ciliary microtubules had close contact with the F-actin network, and that neurite bundles labelled with anti dSap47 antibody as a neuronal marker run along the anterior-posterior body axis. These results indicate that the well-organized cytoskeletal elements and their neural control systems are preserved in P. naikaiensis, and that their mechanisms involved in those regulation systems are similar to those vertebrate systems. Further studies are needed to clarify the physiological mechanisms underlying the muscular and ciliary movements in P. naikaiensis.

Avian coccidiosis is most important entero-parasitic disease in the world. Eimeria parasite is causative agent of this disease. In Japan, this parasite species were widely spread and the positive rates are about 50 in layer and 70 % in broiler. The symptoms of coccidiosis are diarrhea, bloody excretion, weight loss, and die. Eimeria tenella is the most pathogenic protozoa. The sporozoites, infection form of this parasite, entry to epithelial cells around the crypt of cecum in early infection. After infection, parasites proliferate in epithelial cells, and form to sexual stage finally. However, we have less information about the pathophysiology, especially invasive mechanisms and infection route, by E. tenella infection. We have focused to analyze the invasive mechanism and route of this parasite because this phenomenon is first event to cause the pathophysiological changes in the infection. I would like to inform about Eimeria parasite and introduce our research in this paper.

Hibernation is an adaptive strategy for surviving during periods with little or no food availability, by profoundly reducing the metabolic rate and the core body temperature (Tb). Mammalian hibernators store fat extensively in white adipose tissues (WATs) during pre-hibernation period to prepare for hibernation. Thus, they undergo adaptive body remodelling in autumn, the pre-hibernation period, prior to hibernation, whereas little is known about the physiological and molecular mechanisms of the pre-hibernation remodelling. Syrian hamsters (Mesocricetus auratus) are facultative hibernators that can hibernate irrespective of seasons when exposed to prolonged short photoperiod and cold ambient temperature (SD-Cold) conditions. We found that before the initiation of hibernation, the body mass of Syrian hamsters decreased below a threshold, indicating that hibernation in this species depends on body condition. Global profiling of gene expression in various tissues of animals during the pre-hibernation period and hibernation period identified adaptive changes for hibernation at molecular level. Thus, Syrian hamsters as a model animal to study hibernation provide us a unique and convenient opportunity to analyse molecular and physiological mechanisms of adaptive pre-hibernation remodelling under a laboratory condition.

Extracorporeal excretion of mercury by two molybdenum complexes was investigated using mice after injection of metallic mercury or mercuric ion. After injection of metallic mercury into mice, the mice that received the incomplete cubane-type sulfur-bridged nitrilotriacetato molybdenum (IV) complex ([Mo3S4(Hnta)3]2-, referred to as the NTA complex) had the highest mercury content in their urine on the first day, followed by L-cysteine solution and then water. On the other hand, after injection of mercuric ion, the urinary mercury excretion from the mice that received various concentrations of the incomplete cubane-type sulfur-bridged cysteinato molybdenum (V) complex ([Mo2O2S2(cys)2]2-, referred to as the CYS complex) showed a higher level than that of mice that received water (control group). The mercury content in the heart and lungs of the group that received the CYS complex solution decreased in comparison with that of the group that received the water. At the same time, the mercury level in the kidneys for the CYS complex solution group showed the tendency to increase relative to the group that received water.

Runx3 is a transcription factor that belongs to the Runx family. Female Runx3 knockout (Runx3−⁄−) mouse was anovulatory and infertile. Ovarian transplantation experiment suggested that lack of ovulation in Runx3−⁄− mice was caused by alteration of gonadotropin secretion in Runx3−⁄− mice. Cyp11a1 mRNA expression was less in Runx3−⁄− mouse ovaries than in wt ones. Hypothalamic Gnrh1 mRNA was increased, and Kiss1 mRNA expression in the anteroventral periventricular nucleus was decreased, but Kisspeptin mRNA in the arcuate nucleus was increased in Runx3-/- mice. Pituitary Fshb mRNA levels were increased in Runx3−⁄− mice. Cholesterol side-chain cleavage enzyme gene (Cyp11a1) expression was decreased in ovaries of Runx3−⁄− mice. These findings suggest that anovulation in Runx3−⁄− mice was partly due to the alterations in hypothalamus-pituitary-ovary system. Runx3 plays a key role in female reproduction through alteration of gonadotropin secretion.